Such conventional functional ceramic elements (e.g., chip thermistors manufactured by Murata company, Japan, and chip varistors manufactured by TDK) are manufactured through a traditional chip stacking process. In the chip stacking process, green sheets formed of a metal oxide and a binder material and internal electrodes providing electrical connection for the green sheets are sequentially stacked and printed. This operation is repeatedly performed, and then pressing and firing operations are performed on the stacked structure to increase the mechanical strength of the stacked structure and obtain required electrical characteristics.
Functional ceramic components manufactured by this chip stacking process include internal electrodes and a functional ceramic sheet formed of the green sheet converted by firing. The functional ceramic sheet includes an active layer electrically activated by the internal electrodes and cover layers formed on top and bottom surfaces of the active layer for protecting the active layer and increasing the mechanical strength of the functional ceramic sheet.